270 likes | 411 Views
Principles of Immunology Cells of the Immune System 1/26/06. “Those who have health, have hope. Those who have hope have everything.” Arabian proverb. Word List. Apoptosis Granulocyte Hematopoiesis Homeostasis Kupffer cells Necrosis Pluripotent. Hematopoiesis.
E N D
Principles of ImmunologyCells of the Immune System 1/26/06 “Those who have health, have hope. Those who have hope have everything.” Arabian proverb
Word List • Apoptosis • Granulocyte • Hematopoiesis • Homeostasis • Kupffer cells • Necrosis • Pluripotent
Hematopoiesis • Formation and development of blood cells • Begins in yolk sac • Moves to liver and spleen • Moves to bone marrow
PLuripotent Stem Cells • Able to renew at constant rate • Have capacity to differentiate into myeloid or lymphoid progenitor cells
Myeloid Lineage • Granulocytes • Eosinophils • Basophils • Megakaryocytes • Erythrocytes • Dendritic cells
Lymphoid Lineage • T Lymphocytes • B Lymphocytes • Natural Killer Cells
Neutrophils • 60-70% of WBCs • Multi-lobed nucleus • Granulated cytoplasm • Life span is 2-3days • Prominent in inflammatory response • Leukocytosis is marker for infectious process • Actively phagocytic
Eosinophils • ~2% of WBCs • Bi-lobed nucleus • Granulated cytoplasm • Stains with acid dye (eosin) • Prominent in response to parasitic infections • Phagocytic
Basophils • <1% of WBCs • Lobed nucleus • Heavily granulated cytoplasm • Stains with basic dye • Prominent in allergic responses • Non-phagocytic
Monocytes and Macrophages • Large WBCs • Monocytes are circulating precursors • Macrophages • Phagocytic • “Fixed” throughout the body, e.g. Liver (Kupffer) • Activated by cytokines and gamma interferon • APC • Secretes numerous immune response factors
Mast Cells • Found in many different tissues • Contains granules which release histamine • Play role in allergic reactions
Dendritic Cells • Have long “dendrites” • Major role as APC • Stimulated by innate response • Have co-stimulatory molecules constitutively • Have constitutive MHC II expression • Phagocytic and endocytic
Lymphocytes • ~30-40% of WBCs • T Lymphocytes • Mature in thymus • Have TCRs • Recognize Ag on cells only • Two subpopulations
Lymphocytes • B Lymphocytes • Mature in bone marrow • Have membrane-bound Ab(~10,000 per cell) • Go from “naive” to activated. • Plasma cells are Ab secretors • ~1-2 week life span
Natural Killer Cells • Detected for anti-tumor activity • Lack T and B cell markers • Lack Ag receptors • Involved with Ab-dependent cell-mediated cytotoxicity
Homeostasis • Apoptosis vs. Necrosis • Apoptosis • Programmed cell death • Genetically controlled • Macrophages engulf apoptotic bodies • Necrosis • Results from cell injury • Cell contents released • Can trigger inflammation • Genetically controlled • Macrophages engulf apoptotic bodies